Hi there,
I somehow have add this to our host files and it seems that it kept redirect me to
https://www.allanwilliams.ca/. May i know you have set any redirection to your site? Maybe you can give it a check again and kept us updated.
By the way, it seems that currently, those credentials given is missing, and it would be best if you can provided us again with those access credentials in case we can access them once you solved those redirection issues above.
or maybe, you can try steps below and see how it goes.
1. Go to Systems>Global Configuration>Server and disabel ' Gzip Page Compression ' and set ' Error Reporting ' to "Maximum"
2. Go to your composer
3. Open your web console
http://take.ms/zavu0 (right click+inspect element)
4. Add those Youtube URL and check on what error shown on the console
http://take.ms/QQcXh
Please give it a try and see how it goes